wound healing in the tail and scarred wound healing in the limb of lizard Hemidactylus flaviviridis
Lizards are unique in having both – regeneration competent (tail) as well as non‐regenerating appendages (limbs) in adults. They therefore present an appropriate model for comparing processes underlying regenerative repair and non‐regenerative healing after amputation. In the current study, we use northern house gecko Hemidactylus flaviviridis to compare major cellular and molecular events following amputation of the limb and of the tail. Although the early response to injury in both cases comprises apoptosis, proliferation and angiogenesis, the temporal distribution of these processes in each remained obscure. In this regard, observations were made on the anatomy and gene expression levels of key regulators of these processes during the healing phase of the tail and limb separately. It was revealed that cell proliferation markers like FGFs were upregulated early in the healing tail, coinciding with the growing epithelium. The amputated limb, in contrast, showed weak expression of proliferation markers, limited only to fibroblasts in the later stage of healing. Additionally, apoptotic activity in the tail was limited to the very early phase of healing, as opposed to that in the limb, wherein … read more